Field of the Invention
The invention relates to a memory controller and a memory module, and more particularly to a memory controller and a memory module with a synchronization mechanism.
Description of the Related Art
Flash memory is widely used in data storage devices, such as memory cards, USB flash devices, and SSDs, among others. The flash memory is also applied in an eMMC (embedded multimedia card) module. The eMMC module is a multi-chip packaged device where the flash memory chips and the controller chip are integrated.
The embedded multimedia card module generally uses a BGA (ball grid array) package, but now, the multi-chip package (eMCP) has been widely adopted in the embedded multimedia card module. The multi-chip package integrates memory, such as DDR RAM, and the eMMC module, in one package structure. This makes the embedded multimedia card module thinner and more easily adopted for use in portable devices.
The embedded flash memory module using the multi-chip package or the multi-chip packaged chip with DDR RAM needs a test pin from the circuit board for testing by an external testing device. The disadvantage of the testing mechanism is the slow testing speed. Furthermore, to reduce the number of I/O ports, a common interface is usually adopted. The common interface will slow down the testing speed and may cause timing errors. Furthermore, the debug circuit is at the last stage in the traditional embedded memory module, and this design easily causes errors due to data jitter.